I don't know about you, but there's something about tour buses I've come to really dislike. It's that no matter how well versed bicyclists might be in rules of the road, no matter how much room bicyclists are able to give, the bus driver believes that s/he has the road no matter what. From my own experience, I know of two cases in which this took place.
The first example took place several years ago on the Cadilac Mountain Road in Maine's Acadia National Park. On that occaision, I was riding my bicycle up the five-mile long winding road toward the summit. The road had two lanes with a very narrow shoulder bordering the precipice. As I pedaled along, I took as little space in the traffic lane as I could as riding on the shoulder all the way up was impossible. It was cloudy and foggy, but I was brightly dressed with a large, blinking, red light on the back of my bicycle. At one point, I reached the end of a straight stretch of road with a hair-pin tur ahead. It was there that the tour bus came up from behind and passed me with hardly 6 inches to spare. The close call and the air wash of the bus swept me uncomfortably close to the edge of the precipice but I managed to stop in time. After collecting my wits, I rode the rest of the way up to the summit where the driver was sitting alone waiting for his passengers to return. I rolled up to his bus, dismounted, and proceeded to tell him what he did and almost caused. His reply to me was that I shouldn't have been so far out in the road.
The second example took place a few weeks ago while on a group ride involving over 100 cyclists. We were riding back into South Portland, ME on a narrow, two-lane residential street. There were cars parked on both sides of the road with a steep sidewalk on the other side of them. The street also had heavy auto traffic going in both directions, making it more difficult for bicyclists to proceed along the route. On this particular ride, I wore a bright bicycle club shirt, black bibs, and a bright yellow wind jacket. My bicycle was equipped with two BRT-5 white blinkies on the handlebars and red superflash blinkies attatched to the chainstays panier, and helmet Then the tour bus came along. I didn't know it was there until it was almost right behind me. Its driver pulled forward as if he/she would make me a permanent part of the street. I pulled over toward the parked cars, still in danger of either being doored or run over. The bus eventually passed, almost hitting my handlebars. At the end of the ride, I learned that other bicyclists had close calls with the bus.
There is the common saying that bicyclists have the same rights on the same roads. Some bicyclists also believe in "taking the lane" With my luck with tour buses, it seems neither belief works. Those are my thoughts.